Sinker cap mechanism for circular knitting machines



United States Patent 3,273,359 SINKER CAP MECHANISM FOR CIRCULAR KNITTING MACHINES Oscar Fregeolle, Lincoln, R.l., assignor to The Banner Company, Central Falls, R1, a corporation of Rhode Island Filed Jan. 11, 1963, 'Ser. No. 259,863 6 Claims. (Cl. 66--8) This invention relates to circular knitting machines and, more particularly, to those machines for knitting hosiery from the finer counts of yarn. The invention is primarily concerned with improvements in the sinker head and sinker cap for such machine.

It is a general object of the invention to devise a cornparatively simple construction to ensure the maintenance of a concentric relationiship between the sinker head and the sinker cap.

A further object of the invention is that of providing an easily replaceable bearing for restricting the sinker cap against lateral motion relative to the needle cylinder and the sinker head.

It is a further object to provide an inexpensive means to renew worn sinker caps and sinker heads for added usefulness.

A further object of the inventioin is that of controlling the sinker cap against lateral motion without the necessity for outside brackets or supports.

A more specific object is to devise a replaceable bearing which will be easy to insert and will reduce the machine downtime from what is now required.

These and other objects of the invention will become apparent as further details are disclosed. Although a single preferred embodiment of my invention is shown herein, there are a number of modifications that will readily come to mind to one skilled in this art.

In knitting machines for hosiery, where the sinkers are advanced and retracted radially to the needle cylinder, it is usual to incorporate the motivating cams for the sinkers within and upon the under surface of a sinker cap. For a continuing production of first quality knitted material, it is of prime importance to restrain the sinker cap from any lateral motion in order that the distance in which each sinker is advanced may be absolutely controlled.

The sinker cap is maintained in concentric relationship with the needle cylinder entirely by the periphery of the sinker head. While the parts are thus held concentric, the sinker cams remain accurately positioned, but through various forces and pressures upon the sinker cap, unequal wear is introduced, making the cap fit loosely and become eccentric. Metallic and fibrous foreign matter from the adjacent parts and the yarn may also cause wear between the sinker head and the sinker cap.

There are other undesirable factors introduced by the continuous wear on these two contacting parts, such as the black graphite type of deposit which is generated and tends to damage the knitted goods. There is also the possibility of metallic particles remaining in the material which will cause rust spots in the finishing processes. With the instant invention a much cleaner condition results and the type of defect mentioned above is thereby eliminated.

With the replaceable sinker cap bearing herein disclosed, it is an easy matter to remove and replace a worn bearing. Downtime is kept at a minimum because no resetting of the sinker cams is necessary as the sinker cap will become automatically concentric upon replacing the bearing.

The present invention is equally valuable for salvaging worn sinker caps and heads or for use on new machinery. Where it was previously necessary to replace worn sinker caps completely, they may now be reused for only a fraction of the original cost.

3,273,359 Patented Sept. 20, 1966 ICC The invention will be described in greater detail by reference to a specific embodiment thereof as shown in the accompanying figures of drawing, wherein:

FIG. 1 is a plan view of a sinker cap in position over the sinker head;

FIG. 2 is a vertical section taken on line 22 in FIG. 1;

FIG. 3 is a cross section of the sinker cap with the bearing in place; and

FIG. 4 is a cross section of the sinker head with the head bearing in place.

Referring to FIG. 2, a slotted needle cylinder indicated by the numeral 12 together with a plurality of the usual needle retaining spring bands 13 encircling the cylinder in a recess thereof will serve to locate the instant invention with respect to other parts of the machine to one familiar with this art. The drawing illustrates a knitting machine needle cylinder rotatable within an essentially stationary sinker cap, but the present invention should not be restricted to this arrangement.

A sinker head 14 surrounds the upper end of the needle cylinder as at 15 and is rigidly fastened thereto by eight screws 16 which extend through holes bored in the sinker head 14. An external ring 17 projects from cylinder 12 to support and be clamped between a projecting portion 18 of sinker head 14 and four plates 19 through which screws 16 are threaded. Sinker head 14 is fastened to rotate or oscillate with the cylinder 12 and is radially slotted as at 20 for receiving sinkers (not shown) in the known manner.

An annular sinker head bearing comprising a vertical portion 21 and a horizontal portion 22 is made in right angular formation from steel and hardened to resist wear. The vertical portion 21 is located at the inside diameter of the bearing (FIG. 4) and is forced onto sinker head 14 with a press fit into a circular groove machined in the outer periphery of the head.

A sinker cap 23 (FIGS. 2 and 3) is adapted to be placed over sinker head 14 and carries sinker cams on its under surface for advancing and retracting the sinkers during the knitting process. As the sinkers and cams are well known and do not constitute any part of this invention, they are not shown in the drawings.

An annular sinker cap bearing comprised of an axially directed portion 24- and a radially directed portion 25 is formed in right angular cross section with the axially directed portion 24 disposed at the inside diameter of the sinker cap bearing. The lower inside surface of sinker cap 23 is machined with a circular groove to receive the axially directed portion 24 of the hearing which is press fitted into place and positioned by pin 26 inserted into drilled holes through portion 25 and partially into sinker cap 23 (FIGS. 2 and 3). The sinker cap bearing is made from a bearing material which is soft relative to the sinker head bearing.

In operation within a knitting machine, the cylinder 12 together with the sinker head 14 and its hearing will rotate or oscillate and the horizontal portion 22 will vertically support the radially directed portion 25 together with sinker cap 23 both of which remain stationary. Vertical portion 21 will position the sinker cap by close contact with the axially directed portion 24 and maintain the cap in concentric relationship to the needle cylinder 12 and the sinker head 14. Bearing surface A of the horizontal portion 22 will support bearing surface A of the radially directed portion 25 and thus vertically support the sinker cap 23. Bearing surface B of the vertical portion 21 restrains the sinker cap 23 from lateral movement by contact with bearing surface B of the axially directed portion 24.

When it becomes necessary to replace the sinker cap bearing due to wear causing a sloppy fit, a new bearing 3 will bring the parts again into concentricity without further adjustment.

To hold the sinker cap 23 in close contact with the sinker head 14 and yet allow the head to rotate, two L-shaped clamps 27 and 28 are fastened to the outer vertical plane of sinker cap 23 as with screws 29 and 30 and lock washers-31 and 32. Clamps 27 and 28 extend horizontally under the sinker head horizontal portion 22 and serve to restrain cap 23 from unintentional upward motion.

The invention as described provides firm lateral control of the sinker cap throughout the full three hundred sixty degrees and the cap bearing is readily replaceable. It is now possible to renew a worn sinker cap without the necessity for extended adjustments in resetting the sinker cams.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. This invention is, therefore, not to be limited to the precise details described, but is intended to embrace all variations and modifications thereof falling within the spirit of the invention and the scope of the claims.

I claim:

1. In a circular knitting machine, a needle cylinder, a sinker head encompassing the upper end of said cylinder and fastened to rotate therewith, a sinker cap overlying said sinker head, an annular sinker head bearing of angular formation being secured to the outer periphery of said sinker head comprising a vertical portion and a horizontal portion being adapted to support said cap, and an annular sinker cap bearing adapted to overlie said sinker head bearing.

2. In a circular knitting machine, a needle cylinder, a sinker head encompassing the upper end of said cylinder and fastened to rotate therewith, a sinker cap overlying said sinker head, an annular sinker head bearing of angular formation being secured to the outer periphery of said sinker head comprising a vertical portion and a horizontal portion being adapted to support said cap,

an annular sinker cap bearing of angular cross section, said sinker cap bearing comprising an axially directed portion and a radially directed portion, said axially directed portion being adapted to bear upon said vertical portion, and said radially directed portion being adapted to bear upon said horizontal portion.

3. Mechanism as defined in claim 2 wherein said annular sinker head bearing is made from hardened steel to resist wear.

4. Mechanism as defined in claim 2 wherein said annular sinker cap bearing is made from a relatively soft bearing metal being adapted to be easily replaceable.

5. In a circular knitting machine, a needle cylinder, a sinker head encompassing the upper end of said cylinder and fastened concentric thereto, a sinker cap overlying said sinker head, an annular sinker head bearing of angular formation being secured to the outer periphery of said sinker head comprising a vertical portion and a horizontal portion, said cap vertically supported by said horizontal portion, a replaceable annular sinker cap bearing of angular cross section, said sinker cap bearing comprising an axially directed portion being adapted to bear upon said vertical portion and a radially directed portion being adapted to bear upon said horizontal portion, said vertical and axial portions being formed adjacent the inside diameters of each said bearing.

6. Mechanism as defined in claim 5 wherein said sinker cap is heldin concentric relationship to said sinker head by the vertical portion of said sinker head bearing.

References Cited by the Examiner UNITED STATES PATENTS 508,512 11/1893 Franck 66-107 2,740,274 4/1956 Lebocey 66-8 MERVIN STEIN, Primary Examiner. RUSSELL C. MADER, DONALD W. PARKER, R.

FELDBAUM, Assistant Examiners. 

1. IN A CIRCULAR KNITTING MACHINE, A NEEDLE CYLINDER, A SINKER HEAD ENCOMPASSING THE UPPER END OF SAID CYLINDER AND FASTENED TO ROTATE THEREWITH, A SINKER CAP OVERLYING SAID SINKER HEAD, AN ANNULAR SINKER HEAD BEARING OF ANGULAR FORMATION BEING SECURED TO THE OUTER PERIPHERY OF SAID SINKER HEAD COMPRISING A VERTICAL PORTION AND A HORIZONTAL PORTION BEING ADAPTED TO SUPPORT SAID CAP, AND AN ANNULAR SINKER CAP BEARING ADAPTED TO OVERLIE SAID SINKER HEAD BEARING. 